Date: Wed, 11 Aug 2010 10:28:07 -0700
Reply-To: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
Sender: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
From: Dan Blunk <blunk**At_Symbol_Here**UCSC.EDU>
Subject: Old Formalin With Lots of Precipitate


I wondered if you’ve run into this previously:

A physical plant person brought me a pint reagent bottle labeled 37% Formaldehyde this morning that he found while remodeling a workspace.

The bottle is the original Mallinckrodt AR bottle.

It’s about =BE full, and appears to have been opened.

About 50% of the volume of the bottle is a white precipitate, with about =BC volume of clear liquid above.

The purchase date on the label is smudged, but it appears the bottle is at least 35 years old.

As I remember, aldehydes do undergo a slow polymerization reaction. I wouldn’t expect an aqueous solution to form peroxides.




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